1. Field of the Invention
The present invention relates generally to hoists, lifts, and the like, and particularly to a maritime transfer system for transferring personnel and/or equipment to and from a crew boat or vessel and an offshore gas or oil production platform.
2. Description of the Related Art
Offshore or maritime oil and gas drilling and production platforms have expanded nearly worldwide, as oil and gas deposits have been discovered beneath the sea floor in most areas of the world. The construction and maintenance of these platforms have necessitated the transfer of crews and equipment back and forth from land bases to the offshore platforms. This transfer process can be relatively complex, since travel must be accomplished from a stable land base to a platform at sea, and the platform is generally elevated at some distance above the water level.
Larger platforms used for drilling are generally sufficiently large as to require a full time crew and are usually equipped with a helicopter landing pad for the transfer of crews and certain equipment. These large platforms may have some means of accommodating supply boats and ships as well, and additional accommodations to facilitate the physical transfer of personnel to and from the supply boat or ship.
However, there are many quite small offshore platforms that are equipped only for oil or gas production. Many of these platforms have little more than a wellhead and a small surrounding platform, as they are completely automated and require only periodic visits by a crewman for maintenance or inspection, etc. These “normally unmanned installations” (NUT) are not typically of sufficient size to accommodate a helicopter, so that crew members are delivered to and from the site only by a relatively small crew supply boat. As a result, the means for transferring from the boat to the platform and back to the boat is generally primitive, at best. The general means of transfer is by a single rope. The crewman grabs a rope suspended from the platform and swings from the boat to the platform. Clearly, this is potentially hazardous due to motion of the boat relative to the fixed platform from wave action, wind, and/or other forces. There have been instances of serious injury to crewmembers when the crew boat was pushed against the platform structure, where no more than a swing rope was provided for transfer.
Thus, a maritime transfer system solving the aforementioned problems is desired.